A non-pneumatic tire (NPT) may be generally described as including a tread layer that contacts the ground during use, and a subjacent supporting layer that does not rely on inflation pressure for rigidity. For example, the subjacent supporting layer may be formed as an interconnected web of collapsible open cells that are trapped between an inner ring and an outer ring. In such an embodiment, the tread layer is bonded or otherwise joined to the outer ring of the web layer. The inner ring of the web layer is then used to affix the NPT to a wheel, which is subsequently utilized to mount the NPT/wheel assembly to a vehicle.
In a typical pneumatic tire manufacturing process, the various materials from which the tire will be constructed are initially built up in layers around a mandrel to produce an uncured (“green”) tire, and the green tire is subsequently placed in a mold to form the tread pattern, lettering and/or other features, and for vulcanization (curing). In contrast, the tread layer and the web layer of a NPT are formed separately, and subsequently joined to form a complete NPT. Consequently, in order to produce a high quality NPT, both the tread layer and the web layer must be separately manufactured with precise tolerances, and at least the inner surface of the tread layer and the exterior surface of the web layer outer ring needs to remain highly flat in order to result in proper bonding of the tread layer to the web layer.
The inventor is presently unaware of an efficient device and/or process for precisely and repeatably molding a NPT tread layer and, therefore, there is an unmet need for the same. Exemplary mold and molding process embodiments described herein satisfy this need.